1. Field of the Invention
This invention relates to cooling tower fill assemblies and particularly to an improved splash bar construction for use in crossflow cooling tower installations.
2. Description of Prior Art
Two general orientations for splash bar fill assemblies are known in crossflow cooling tower design. In the more common type, a matrix of horizontally oriented splash bars is disposed with the longitudinal axis of the bars transverse to air flow. When bars are disposed in this orientation, the vertical dimension represents an obstruction to transverse flowing air, which results in high resistance and high induced pressure drop, thereby requiring more energy to induce air flow through the cooling tower and reducing the overall cooling efficiency and economy of operation than might otherwise be obtained. The vertical dimension of said splash bar is usually substantial because of strength and stability requirements of practical and economical fill support and assembly configurations.
Of necessity, splash bars whose longitudinal axis is transverse to air flow must present a relatively low vertical profile, and such shapes compromise strength, which must be compensated for by heavier bars and/or closer spaced support elements. Patents representing this configuration are U.S. Pat. Nos. 3,647,191; 3,468,521; 3,389,895.
A second type of crossflow matrix orientation is known wherein air flow is parallel to the longitudinal axis of the splash bars. Representative configurations include rectangular shaped cross section (U.S. Pat. No. 2,497,389), sinusoidal cross section (U.S. Pat. No. 3,758,088) and the perforated Z, C or I cross sections (U.S. Pat. No. 4,020,130). Each of the splash bar sectional configurations heretofore disclosed wherein the splash bar longitudinal axis is parallel to air flow has particular distinguishing features and characteristics. The differences are subtle, but nevertheless critical. For example, the sinusoidal cross section has a lower cooling efficiency because it does not present a flat surface element to falling liquid which would maximize splash-induced fragmentation of falling liquids, into droplets. It is also subject to a lateral displacement from its normal position. The Z, C or I shape splash bar configurations have the advantages of a flat horizontal splash surface and reasonable structural stability when they are supported on all sides in a grid of suitable strength and rigidity. However, each has minimal or even negative lateral directional control over falling liquid flow, each has a tendency to develop non uniform liquid flow which can reduce cooling efficiency, and each is relatively unstable laterally, which requires that the upper surface element be held in place by an overlying horizontal support element. Much remains to be done to optimize the performance of a splash bar fill assembly, and particularly to develop ultimate functional cooperation between the elements of the structure.